1. Field of the Invention
The present invention relates generally to motorcyles; and, more particularly, the invention relates to the forward mounted wheel on a motorcycle and the suspension and braking system used in connection therewith.
2. Description of the Related Art
Harley-Davidson Motor Co. of Milwaukee, Wis. introduced a "springer" motorcycle in the early 1900's. As seen in FIG. 1, this early generation springer had a suspension system which utilized an elongate rocker 41 (with grease fittings 41a) secured to the front wheel axle. Also secured to the rocker 41 were a rigid fork 35 and a springed fork 37. Shock absorbing springs 32 were mounted adjacent the handlebars and were designed to minimize shocks from bumps or holes of a road surface on which the cycle was driven.
The front wheel rocker suspension system suffered from several shortcomings. First, as seen in FIG. 2, the rocker 41 was mounted to the forks with single-shear studs 43 and bushings which were subjected to heavy wear. As these elements wore, a certain amount of clearance developed between the elements, thereby allowing several degrees of freedom in rotational movement and a deterioration of comfort and handling. This in turn created even more wear. As a result, these parts had to be periodically replaced.
A second shortcoming of the early generation springer's suspension system was that, while the shock absorbing springs 32 took the "jolts" out of the ride, the ride was nevertheless "bouncy" due to the springs 32. Driving over rough roads would create a very bouncy ride. Similarly, it was not uncommon for the suspension to "bottom out", that is, reach the maximum shock absorption limit of the springs 32, with considerably less force applied to the suspension system than would be desirable.
Finally, a bottoming out problem also would arise when the cycle was stopped quickly. The forward momentum of cycle and rider would drive the handlebars and front suspension forks forward and downward, thereby eliminating shock absorbing capability after the suspension had bottomed out. In the present invention, the suspension and brake mechanisms work in concert to reduce that problem.
Because the springer type motorcycle possesses several very advantageous performance attributes, applicant has sought to improve it. The suspension system incorporated is considerably more sensitive to smaller bumps and irregularities of the road as compared to suspension systems in motorcycles which use telescoping fork legs on either side of the wheel between the axle and the frame. This is because the hydraulic cylinder and piston are pulled slightly out of alignment due to the vertical pull of gravity and therefore the edge of the piston rubs against the inner surface of the cylinder.